A generator is a device capable of transforming mechanical energy into electricity. This transformation is achieved by the action of a magnetic field on electrical conductors. If a relative movement between the conductors and the magnetic field is produced, an electromotive force is generated in the conductors.
The abovementioned electrical conductors usually consist of winding arrangements and the magnetic field may generally be produced by electromagnets or permanent magnets. The electromagnets may also comprise winding arrangements, which may be supplied with suitable power to generate the magnetic field. For reasons of homogeneity of terms, the winding arrangements having the role of generating the magnetic field will be referred herein as “magnetic field winding arrangements”, and the winding arrangements in which an electromotive force is induced by the action of the magnetic field will be referred herein as “power producing winding arrangements”.
In order to achieve relative movement between the power producing and the magnetic field winding arrangements, rotation of the power producing winding arrangements, or rotation of the magnetic field winding arrangements, or rotation of both may be caused. Such a rotation may be achieved by operationally connecting the corresponding winding arrangements with e.g. a turbine comprising blades. The rotation of the turbine may be caused e.g. by the wind or a waterfall or steam acting on the blades. This steam may be produced e.g. from an energy source which may be fossil or nuclear fuel.
In some known generators, each of the power producing winding arrangements and/or the magnetic field winding arrangements comprises at least an inner coil and an outer coil constituting a concentric structure of coils. The inner coil is constituted by a determined number of layers of an inner conductor and, equivalently, the outer coil is constituted by a determined number of layers of an outer conductor, the inner conductor being wound around a tooth. This concentric structure permits increasing the number of layers of the winding arrangements in comparison with winding arrangements based on a single coil with a determined number of conductor layers.
In the case of magnetic field winding arrangements, a higher number of conductor layers permits generating a higher magnetic field, whereas in the case of power producing winding arrangements, a higher number of conductor layers allows induction of a higher voltage.
In operation, the current passing through the coils causes the winding arrangements to heat up. Overheating of the conductors may damage the generator and/or decrease its performance.